The design for this one should be obvious.
Obviously,

• Vowels form the big ring.
• Voice and unvoiced consonantal pairs tend to be grouped:
  • B and P
  • S and Z
  • T and D
  • G and K
  • V and F
• V has some special friends.
  • U and V, being once used interchangeably, are found side-by-side.
  • W, being the little brother of V that just acts bigger to boost its ego, likewise appears nearby.
• Some letters that are alphabetically close are placed physically close:
  • L, M, and N form a line. They are also close to R since they can all be vowel-like. (This also places them near the middle of the vowel ring.)
  • The aforementioned W, U, and V lie in a line, and lie in a game of poker, so be careful.
  • W also seems to be found near its alphabet buddy X (sing the song and you'll see what I mean!)
  • H, I, and J are linear, especially since I and J are evil twins (both twins, both evil).
  • G and K form a teeny line that hangs out with H, I, and J.
• R goes near D and L near Z since, when strongly anunciated, these liquids resemble those consonants.
• Y joins R and L as a liquid, and gravitates, of course, toward I.
• Q and X are often used in transliterations to denote uvular flaps that resemble the breathy consonant H, placing H across the board from them.
• Q and X also share the property of being used almost exclusively in phonetic clusters with K, directly opposite the board.
• A and B as well as D and E are in proximity since they form in-order pairs, likewise P and Q.
• C is a curvy letter resembling O which often takes the sound of S, thus drawing those two near.

"Well, of course!" you say.